Influence of the Temperature, Type of Salt, and Alcohol on Phase Diagrams of 2-Propanol + Inorganic Salt Aqueous Two-Phase Systems: Experimental Determination and Correlation

Abstract

The liquid−liquid equilibriums (LLEs) for 2-propanol + tripotassium phosphate + water at 298.15, 308.15, and 318.15 K and 2propanol + dipotassium hydrogen phosphate + water at 298.15 K were measured. The binodal curves of 2-propanol + potassium sulfate/potassium sulfite + water at 298.15 K were measured and compared. Accordingly, the experimental binodal data were correlated using Merchuk, Hu, and Pirdashti equations, and the tie-line compositions were correlated using Othmer− Tobias and Bancroft equations. The effect of temperature, anion type, and length of alcohol chain on the binodal curve, tie-line length (TLL), slope of tie-line (STL), and phases' physical properties were studied. It was found that an increase in salt's hydrophobicity and alcohol's carbon number in low temperature led to the expanding biphasic region and approaching the binodal curve to the origin. The phase-forming ability of different anions was studied using effective excluded volume (EEV) model, and the relation between the EEV value, saturation solubility, anion's surface charge density, and salt solubility in water was investigated. It was found that kosmotropic ions with higher surface charge density and lower solubility in water have a higher EEV value and are able to form a wider two-phase area. Finally, the salting-out ability of different alcohols was compared with the Setschenow-type equation, and it was found that increasing the carbon number of alcohols enables the ATPS to salt out effectively.

Phase Equilibria of Aqueous Two-Phase Systems of PEG with Sulfate Salt: Effects of pH, Temperature, Type of Cation, and Polymer Molecular Weight

“…The impact of cation on the two-phase area is shown in Figure . Due to its higher surface charge, the zinc cation is found to be able to form a larger phase diagram …”

“…Due to its higher surface charge, the zinc cation is found to be able to form a larger phase diagram. 34 3.7. Binodal Curves and Tie-Lines Data Correlation.…”

Temperature, Polymer Molecular Weight, and Salt Effects on Phase Equilibria of PVP + Formate Salts + Water: Experimental Measurements, Correlations, and Thermodynamic Modeling

“…The experimental procedure has been described in detail in the previous studies, , and all apparatus used in this study were essentially the same as in our previous work. − The binodal data of all the PVP-organic salt ATPSs were determined by the titration method. , The solubility of the salts and PVPs in water was determined according to the turbidity measurement in 5 K steps, and the obtained data are presented in Table S1. The stock solution of salt (50 wt %) was added dropwise to the stock of PVPs (concentrated solution) to form a turbidly two-phase solution.…”

Effect of temperature on the phase-separation ability of KCl in aqueous two-phase systems composed of propanols: Determination of the critical temperature and extension of the results to other salts

“…It is well known that the short-chain alcohols methanol, ethanol, 1-propanol (1P), 2-propanol (2P) and tert-butanol are completely miscible in water at any temperature above the freezing point. However, the presence of certain salts in sufficient concentration can cause splitting of the mixture into two liquid phases [4][5][6][7][8][9][10][11][12], both containing a high concentration of water. This can lead to an ATPS that could be used in the aforementioned separations.…”